EP-A 058 029 discloses a multifunctional card with a purse function. The multifunctional card used here distinguishes several bank areas, a credit-card area and a purse area. The user is able to gain access to a bank or credit-card area with the aid of a personal identification number (PIN). The user can now reload a certain sum of money from this area to the purse area and then utilize this sum to avail himself of services or goods without entering his PIN.
EP-A 058 029 contains no information about how the load operation is protected from fraudulent manipulations.
The load operation of a purse is generally performed via an apparatus (terminal) which is within the sphere of responsibility of the purse supplier. The load process necessarily includes the bank application of the card which is within the sphere of responsibility of the bank. Communication is thus necessary between the components of the system within different spheres of responsibility, so that it is necessary in the interests of all institutions participating in the system to make the total process resistant to forgery and to ensure the integrity of the secret information required in the various components of the system.